Mike Williams wrote:
[ ... ]
>Take a look at the "object" pattern. It allows a surface to have a
>different texture wherever it intersects a second invisible object. Your
>thingie can be coded like this:
>
>#declare thingie = sphere {<0,0,0>,15
>  pigment {
>    object {
>      cylinder {<-4,0,-20>,<-4,0,-10>,4}
>      rgb <1,1,1>
>      rgb <.6,.6,.8>
>    }
>  }
>}
>
>Mike Williams
>Gentleman of Leisure

I was just looking for a solution to the exactly the same problem when I
found this useful thread, which worked fine. I then tried making
the intersecting invisible object partialy transparent, which didn't give
me the result I was expecting:

sphere
{
    0, 5
    pigment
    {
        object
        {
            sphere  { <0,0,-5> 3 }
            pigment { Green }
            pigment
            {
                bozo
                color_map
                {
                    [0.5 rgbf <1,1,1,1>]
                    [0.5 rgbf <1,1,1,0>]
                }
            }
        }
    }
}

I had expected to see a white splodge bounded by a circle on the green
sphere, whereas it looks like a white splodge hovering infront of a
cut-away green sphere.

Is it possible to do it this way, or do I have to repeat the Green
(or whatever pattern) in the color_map or do I have to make the intersecting
object the white splodge shape ?

Thanks,

Bernard

Post a reply to this message